Codec AVOption b (set bitrate (in bits/s)) specified for output file #0 (/wowza/users/j/l/jlovelet/HD720/oJAFxvqygTeeeJihlkIT_temp.mp4) has not been used for any stream. The most likely reason is either wrong type (e.g. a video option with no video streams) or that it is a private option of some encoder which was not actually used for any stream.

The How? lots of googling, some dumb luck, trial and error. What exactly does this mean? There are many cookbook recipes that say “use this” but finding a guide to the syntax was tricky. I eventually found this article which said,

“The expression trunc(ow/a/2)*2 as vertical resolution means: use as output height the output width (ow = in this case 1280) divided for input aspect ratio and approximated to the nearest multiple of 2
“This command line uses as width the minimum between 1280 and the input width (iw), and then scales the height to maintain the original aspect ratio. Notice that “,” may require to be escaped to “\,” in some shells.”

I tries the same with width, but it didn’t like that divide by a bit, but it did like